The distinct peripheral cytosolic proteins, alpha, beta and gamma-catenin (102, 94 and 86 kDa) found in many tissues bind to the conserved cytoplasmic tail domain of the cell-adhesion cadherins. Catenins link E-cadherin to other integral membrane or cytoplasmic proteins and are modulated by Wnt-1 proto-oncogene. They are good candidates for mediating transduction of cell-cell contact positional signals to the cell interior. Absence of alpha-catenin is found in certain tumor cell lines and r